1. Field of the Invention
The present invention relates generally to methods for repelling rodents, and more particularly to a method for repelling rodents and vermin from structures, yards, gardens, and agricultural fields areas using dry dusting sulfur irritate the mucous membranes of such pests.
2. Description of the Prior Art
It is well known in the art to repel residential pests and vermin on the one hand, and garden and crop damaging rodents and birds on the other, through the application of chemicals to the area being protected. The prior art includes some repellents in powdered form. However, the various application methods, particularly in the garden and field setting, typically employ aqueous solutions of repellent and further depend upon mixing the repellent in soil or applying the repellent to crops or structures that the pest will taste or smell. Most notably, prior art repellents depend upon an extremely foul smell and taste. Such repellents are only partly effective. The pest can move about with relative impunity should it merely bypass, and not taste or smell the repellent.
In some applications, powdered repellents can be more effective than aqueous repellents. Prior art powdered repellents include U.S. Pat. No. 4,795,637 by Harding, Jr., which teaches a rodent repellent in powder form comprising thujone oil with a powder that does not atomize readily when agitated. Such powders include lime powder, borax powder, pyrethrum powder, silica gel, sulphur powder, sabadilla, pepper powder, tobacco dust, and other powders within a density range of 0.9 grams/cubic centimeter to 1.0 grams/cubic centimeter and of moderately course particle size.
Another powdered repellent is found in U.S. Pat. No. 4,025,643 by Warner, which discloses a free-flowing rodent repellent in which a rodent repellent effective N,N-dialkylsulfenyl dithiocarbamate is admixed with a chemically inert grinding aid having a density of 5 pounds per cubic foot or less to form a non-caking composition. A solids suspending agent, inert to the N,N-dialkyl-sulfenyl dithiocarbamate, and a wetting agent are admixed with the rodent repellent and the grinding agent to produce a water-dispersible, free-flowing powder.
U.S. Pat. No. 631,738 by Dowie teaches a powdered rat repellent consisting of twenty percent chili pepper, five percent hellebore, eight percent sulphate of lime, eight percent phosphate of lime, fifty-four percent carbonate of lime, and five percent oxide of iron. The hellebore and pepper are mixed with a medium to form a light powder that floats and disburses when disturbed. The powdered composition is intended to be sprinkled on infested premises.
Non-powdered compositions include U.S. Pat. No. 5,879,696 by Blumberg discloses a repellent comprising capsaicin or capsaicin derivative compounds. The "hot" compounds are intended to repel animals having capsaicin sensitive receptors.
U.S. Pat. No. 5,674,496 by Etscorn et al., discloses various methods for extracting the active repellent ingredient from pepper plants, particularly habanero peppers, and for using the extract to treat the objects to be protected.
U.S. Pat. No. 3,941,887 by Hermann et al., teaches a variety of repellent compositions and methods for repelling warm-blooded animals, such as rodents, birds, leporines, and ruminants, comprising N(-alkyl, cycloalkyl, phenoxycarbonyloxyalkyl, phenyl, alkyl-phenoyl and alkyl-chlorophenyl)-dithoibiuret derivatives.
U.S. Pat. No. 4,058,402 by Stansbury et al., teaches a water soluble rodent repellent for coating onto buried objects such as cables. Any water soluble or water dispersible composition can be used, but the preferred embodiment disclosed comprises N,N-dimethylsulfenyl dithiocarbamates combined with dimethylsulfoxide and polyvinylalcohol or with one of dimethylsulfoxide and dimethylformamide, and with a hydroxyalkyl cellulose.
The prior art compositions and methods fail to appreciate the advantages of using simple dry dusting sulfur as an eye and mucous membrane irritant to repel burrowing rodents and other pests. Admittedly, some prior art pest repellents include sulfur as an ingredient among others in compositions. However, such compositions necessarily include other ingredients to enhance or give rise to some desirable repellent property or effect. The present inventor has determined that for purposes of repelling several types of pests, simple dry dusting sulfur, with absolutely no other ingredient whatsoever, gives superior results.
Further deficiencies of prior art repellents include high water solubility, rapid deterioration and decrease of effectiveness, costliness, toxicity to humans, and lethality to rodents (resulting in kills that decay in or near living and work place structures).